WASHINGTON, Jan. 21 (UPI) -- Several clusters of a rare brain disorder known as Creutzfeldt-Jakob disease have popped up in the United States in recent years and although none has been linked to the consumption of mad-cow-infected meat, J.P. Morgan Securities, the financial analysis firm, has advised its investors the cases could affect the beef industry negatively.
Even if the clusters are due only to coincidence, increased media attention and the public's perception could lead to a decrease in beef consumption, particularly in light of the case of mad cow found in Washington last month, a group of J.P. Morgan analysts led by Pablo Zuanich in New York City wrote in their Jan. 13 advisory, which was obtained by United Press International.
All six of the clusters identified by Zuanich's team have been attributed by public health officials to sporadic CJD, also known as sCJD, which is not tied to mad cow and generally affects people over age 55. Another form of the disease, called variant CJD, is thought to be caused by eating mad-cow-infected meat and typically affects those under age 30.
Still, Zuanich and his colleagues question if vCJD cases were overlooked in the clusters, particularly because recent research in mice has suggested both sCJD and vCJD can be caused by the mad cow pathogen.
"The existence of clusters raises the question of 'contamination' or 'infection,' and also raises the hypothesis that rather than cases of sCJD these might have been cases of vCJD," the advisory said, adding: "Given that sCJD occurs randomly in one out of one million cases, it is a statistical rarity to find an sCJD cluster -- let alone six."
The clusters cited by the analysts include those in the southern New Jersey area (2000-2003), Lehigh, Pa., (1986-90), Allentown, Pa., (1989-92), Tampa, Fla., (1996-97), Oregon (2001-02), and Nassau County, N.Y. (1999-2000).
Some of the clusters described by the analysts involved as many as 18 deaths, and ranged from a rate of four to eight cases per million people -- or four times to eight times as high as the national average.
The impact renewed attention towards these clusters could have on the beef industry remains unclear but "new cases of infected cows and/or a wider debate of CJD clusters could indeed have an effect on beef sales," Zuanich and his colleagues said.
The beef industry doubts there would be much of an impact even if there is widespread media attention.
"It really will not, we feel, have an impact on the beef industry, nor should it," Dan Murphy, spokesman for the American Meat Institute, an industry trade group in Arlington, Va., told UPI.
"We are most encouraged by data showing an incredibly high percentage of consumers remain convinced and confident, as they should be, that beef products they buy are safe," Murphy said.
Steve Mitchell is UPI's Medical Correspondent. E-mail firstname.lastname@example.org